Coupling and connecter for electric conduits and outlet boxes



L. G. TERRY COUPLING AND CONNECTER FOR ELECTRIC CONDUITS AND.OUTLETBOXES Filed OCT.. l5. 1954 agi Patented Aug. 17, 1937 UNITED STATESPATENT OFFICE COUPLING AND CONNECTER FOR ELECTRIC CONDUITS AND OUTLETBOXES 7 Claims.

My invention relates to a type of coupling or connecter for attachmentto conduits, or the like, or to outlet boxes, or for connecting twoconduits in which the coupling attaches to the 5 conduit by a grippingpressure around the peripheral surface of the conduit and thus securelyattaches the coupling to the conduit, and with my construction, thecoupling may be attached to the electric outlet box, or the like, or thecoupling may be formed integral with certain types of outlets.

My invention in its broader aspect relates to a coupling or connecter inthe form of a sleeve with an internal shoulder. The conduits t in- 15side of the sleeve and the'end of the conduit engages the shoulder, orif two conduits are used, engage opposite shoulders. The sleeve' has arigid portion forming the main annular body and an end portion which isresilient and contractible preferably by having longitudinal slits inthis contracting portion. With this assembly I utilize a wedging collarwhich surrounds the contractible portion of the sleeve and either thesleeve or the collar may have a slight taper so that the 5 collar may bedriven or wedged tightly on the exterior of the sleeve and thus contractthe sleeve due to the longitudinal slits, to gripl and form a tightconnection with the conduit.

A further object and feature of my invention as it relates to mostconstructions is in providing the contractible portion of the sleevewith a surface of gradually increasing diameter from its point ofconnection to the rigid part of the sleeve, thus making a slightlyoutwardly extend- 35 ing taper. This taper may, however, if desired, beadjacent the extreme end of the sleeve. With this type of sleeve thecollar is preferably cylindrical on its inside surface and has asufficiently loose fit that it may slide longitudinally on the portionof the sleeve of the least diameter, but wedges against the.outwardlyexpanding end, and therefore, when wedged tightly against thisexpanding portion the slits are contracted and a tight grip is obtainedbetween the resilient por- 45 tion of the sleeve and the conduit fittedwithin the sleeve.

Another characteristic of my invention is in forming the sleeve withthreads on the rigid portion, which threads may be screwthreaded in an50 outlet, an angle box, or the like, used in electrical wiring.

Another modication is to form the sleeve integral with an angleconnection, or the like, in which the resilient portion of the sleeve ismade 55 tubular and has the longitudinal Aslots therein.

The slots or kerfs allow contraction of this sleeve surciently to pressor t the collar thereover before inserting the conduit in the sleeve.

A further modification of my invention as it relates to the attachmentof the coupling or connection to an outlet box is in providing the rigidportions of the sleeve with external threads on which is threaded a nutwhich engages inside an outlet box and by tightening the nut, the collaris wedged against the expanded end of the split sleeve.

Another object and feature of my invention is in forming a coupling forattaching two conduits end to end. This employs a sleeve with a rigidcentral section having two internal shoulders spaced apart by aninternal rigid section. This sleeve has longitudinal splits at both endportions. The entire sleeve is preferably cylindrical on its outsidesurface except that adjacent one end which expands outwardly to form awedging surface. In conjunction with this type of sleeve I employ awedging or locking collar which is substantially the samek length as thecomplete sleeve and is cylindrical on its inside surface except adjacentone end in which it has an inward taper. The collar is designed to havea close sliding t on the sleeve so that it may be inserted over thenon-expanded end of the sleeve and when the collar is wedged into iinalposition the leading end of the collar engages the outward expandedportion of the sleeve and the inwardly tapered end of the collar engagesthe opposite end of the sleeve. Thus, the resilient end portions of thesleeve having the splits are simultaneously contracted and engage orgrip the two conduits inserted in the sleeve.

My invention is illustrated in connection with the accompanying drawing,in which:

Fig. l is a side elevation showing a use of my invention in connectionwith an elbow type of electric cord outlet.

Fig. 2 is an enlarged view, the features of my invention being shown indiametrical section.

Fig. 3 is a modification in which the sleeve is formed integral with theoutlet tting.

Fig. 4 is a longitudinal section showing the use of my invention in anoutlet box, or the like.

Fig. 5 is a longitudinal section showing a coupling or connection oftwoconduits.

Fig. 6 is a transverse section on the line 6 6 of Fig. 5 in thedirection of the arrows..

Dealing first with the construction shown in Figs. l and 2, the sleeve II is illustrated as havjing a rigid section I2 which is screwthreadedexternally at I3. -This sleeve has a resilient end of the conduitabutting against the shoulder I6.

This shoulder therefore forms a stop limiting the insertion of theconduit. A collar 22surrounds the sleeve and m-ay be inserted over therigid threadedend. This collar has a sliding fit on the major portion ofthe section having'the slots. The inside surface of this collar ispreferably cylindrical so that when forced towards the end ofthe sleevehaving the -wedge or cam surface 20, this surface whichris annular,except for the slots,

' is contacted substantially by an inner edge of the collar which causesa compression or wedging of the outer portions of the compressiblesection of the sleeve and thus tightly grips the conduit. With myconstruction when properly executed,

-the conduit may be gripped with suflicient tightthe collarV 22jammedoutwardly to firmly attach Vrigidrand provided with a shoulder 3|.

ness so that the conduit and the sleeve and collar function as a unitallowing the conduit with the sleeve to be threaded if desired in thefitting 23 which is internally threadedat an opening indicated -at 24.However,-if desired, the sleeve with the collar can first be secured totheY fitting then .the conduit maybe inserted in the sleeve and theconduit to the sleeve.l and thus to the fitting.

In the construction of Fig. 3 the fitting 29 is provided with what maybe termed a sleeve section at oneof the openings,`this section being Thecompressible section 32 of the sleeve is provided with "a plurality oflongitudinal slits 33. This is preferably cylindrical onthe insidesurface v34 and the major portionof the outside surface 35 iscylindrical except for a cone-shaped cam `surface 36 adjacent Vthe outerend which forms thewedge.

Vand 3 may be substantially similar.

jA collar 31 is employed inthe construction of The Wedge construction ofFigs. 2

Fig. 3 which is similar to the collar 22 of Fig. 2.

l Such collar is preferably cylindrical on its inside surface; Y.

The collar of Fig. 3 is slipped over the end of the split section of thesleeve prior to the insertion of the conduit 38, the slots 33 beingnarrowed sufficiently to pass the collar over the enlarged Fig. 2, thesleeve as a wholeY being designated by outwardlytapered end of thesleeve. The sleeve on account ofits resiliency thenresumes its normalform and the collar is maintained in place even when loosely fittingonthe portion of the sleeve onrwhich it has a sliding fit. The conduit fis insertedruntil its end contacts with the shoulder 3|; 'I'he collar isthen Ypressed 'outwardly against the wedge portion 36and thus securelyattaches the conduit to the sleeve section of the fitting.v Inattachingthe collar in the constructions of Figs. 2 and 3 it ispreferably struck by a hammer or similar tool to', drive it firmlyv ontothe wedge or cam end ofthe split sleeve.

In the construction of Fig. l I utilize a sleeve, collar and conduitlsubstantially the same -as in the assembly numeral 40 in which itrhasthe rigid exteriorly: threaded section '54Ifand Vthe compressibleportion 42 with the longitudinal slits 43. The

rigid section is provided with a stop shoulder 44 toengage the end ofthe conduit 45. The outer surface 46 of the compressible sectiondiverges outwardly, forming a wedge adjacent its end.v The collar 41 ispreferably fitted on the sleeve over the threaded end.

In the mannerof assembling shown in Fig. 4

a wall 48 of an'outlet box, or the'like, is provided Y with the usualperforation 49 for the insertion of the threaded end of the sleevef40. Anut 50 .is then Vthreaded on the threaded section Yand tightened againstthe inside of the wall48. The

collar-41-engages against the outside of this wall .andi on tighteningthe nut 50, the collar is wedged on the collar orwedging of the sleeve.y

Thus,;ifrit'is;desired to attach the conduit to the' sleeve and thentighten the sleeve and thus grip the'conduit, the procedure may be asabove surface on the exterior defined in which the tightening of theynut causes al wedging of the coll-ar 41 on the split portion of thesleeve. Howevenif desired, the conduit may be fitted in thesleeve andthe collar tightened to grip the conduit before the assembly on the boxand thenthe nut 50 may be tightened to hold the assembly of the conduit,sleeve and the collar in place. Y Y

In the construction of Figs. 5 and 6 thersleeve is designated bytheassembly numeral 55. This has a rigid central section 56 with twoshoulders 51 and 58 spaced apart-byaninternal annular rigid section 59.Extending outwardly from one end of the central rigid section there .isacompressible section 60 of the sleeve and fromthe opposite side there isanother compressiblesection 6 I, both of these sections being provided.with longitudinal Vslits 62. The sections 60 and ..6I

and the rigid portion of the 'sleeve adjoining the Y shoulders arepreferably cylindrical same diameter.

The outer surface 63 of the sleeve section 6I) is, cylindricalthroughout its entirelength. A porand of th tion 64 of the outer surfaceof the section 6I ad-Y jacent the rigid section is also cylindricalbut'the outer end has an'expanded wedging portion 65 graduallyincreasing in diameter. The conduits 66 and 61 are inserted respectivelyin the sleeve portions 60 and 6I until they contact the respectiveshoulders 51 and 58. The sleeve is lockedto the conduits by meansof thecollar. This collar is preferably approximately .the same length as thecomplete sleeve and from the leading end 69 has the major portion of itsinside surface 10 cylindrical, except that adjacent theA rear end 1Ithere is an inward wedging taper `12. The collar is of sufficientdiameter so that the inside' cylindrical portion will have a sliding fiton the outside cylindrical surface of the sleeve. 'I'he expanding wedgeor outward cam on the sleeve is so proportioned to the inward taper 12on theinside of lthe collar that the end portion 69 of the collarcontacts the wedgesurface 65'at the same time the inward taper 12 ofthecollar contacts the op# posite endy of the sleeve. Then,when Vthe collaris wedged endwise on the sleeve by being struckv on the end 1IV bya'rhammer, or the'like, the collar becomes wedged or locked on thesleeve and by the contraction of the split end portions of theA "70sleeve thus formingpa iirmand rigid connection sleeve the conduits arefirmly attached tothe between the two conduits.` Y Y It'will be notedthat a characteristic feature of my'invention is that the longitudinalsplits in the sleeve start in therigid portion ofthe sleeve andterminate, at the free end of the sleeve. The contractible portions ofthe sleeve lbetween the splitsv are as to their outsidel surface conedoutwardly so that the portion of the sleeve adjacent its free end is oflarger outside diameter than adjacent the terminal ends of the s-plits.-Hence when the sleeve is attached to a rigidstructure thejcollar must beforced outwardly in order to form a wedging contact with thecontractible sections of the sleeve, that is, the collar must be forcedaway from the rigid portions of the sleeve towards the free ends of theportions between the splits. Therefore if a connection is made to astructure subject to vibration, the collar cannot slide off of thesleeve, but if it should loosen under vibration, it would still be heldfrom slipping off of the sleeve.

Another characteristic feature of my invention is that the internalshoulder of the sleeve is formed in the rigid structure inwardly fromthe termination of the splits.

Various changes may be made in the details of construction withoutdeparting from the spirit or scope of the invention as defined by theappended claims.

I claim:

1. In a coupling, a sleeve having a rigid section with an internalshoulder, a portion of the sleeve extending from the rigid section to afree end and having longitudinal splits such portion being cylindricalon the inside surface, a pipe having a close t against said surface withits end engaging the shoulder, a collar of greater inside diameter thanthe rigid portion of the sleeve and insertable thereover, one endportion of the collar and the end portion of the sleeve remote from therigid structure adjacent its free end having complementary wedgingsurfaces whereby on longitudinal movement of the collar in reference tothe sleeve, the split portion of the sleeve away from the rigidstructure toward the free end is contracted to grip the said pipe, therigid portion of the sleeve having a second internal shoulder and aportion extending therefrom to a second free end having longitudinalsplits and a cylindrical inside surface, a second pipe fitted in thesaid second cylindrical surface of the sleeve and engaging the secondshoulder, the second free portion of the sleeves and the collar havingcomplementary wedging surfaces whereby on a longitudinal movement of thecollar in reference to the sleeve, both free end portions of the sleeveare contracted to engage both pipes in the sleeve.

2. In a coupling, a sleeve having a central rigid portion with oppositeend parts having longitudinal splits extending to the opposite free endsof said portions, two pipes each inserted in the sleeve from theopposite free ends, one of the free end portions of the sleeve having anexpanding conical wedging surface, a collar insertable over the oppositeend of the sleeve and being of larger inside diameter than the rigidportion of the sleeve, said collar having an inside surface on one endengaging the cone surface of one end of the sleeve, the said collarhaving an internal cone surface with the smallest part of the coneadjacent the end of the collar opposite the portion of the collarengaging the cone surface of the sleeve whereby on longitudinal movementof the collar in reference to the sleeve both of the free end portionsof the sleeve are simultaneously contracted to grip the two pipes.

3. In a coupling as claimed in claim 2, the central rigid portion of thesleeve having two internal shoulders spaced apart by an annular section,the end of each pipe engaging a shoulder and the ends of the pipes beingspaced apart by the said annular section.

f 4. In a, coupling, a sleeve having a rigid portion and having aplurality of longitudinal splits terminating at their inner ends at therigid portion and extending to the free outer end of the sleeve, thesections of the sleeve between the splits being compressible inwardly,the compressible portions of the sleeve on their outside surface beingoutwardly coned towards their free ends, whereby the outside diameter atthe free ends is greater than the diameter adjacent the rigid portion,an internal shoulder in the rigid portion of the sleeve, a pipe fittedin the: sleeve from the free end and engaging the shoulder, a rigidcollar cylindrical on its inside surface surrounding the sleeve, thecollar having a forward end, the collar being movable to move theforward end away from the rigid portion towards the outwardly conedsurface of the contracting portions of the sleeve and thereby compressthe contracting portions between the splits to clamp the pipe.

5. In a coupling, a sleeve having a rigid end portion with an internalshoulder, a plurality of longitudinal splits extending from the rigidportion and terminating at the end of the sleeve remote from the rigidportion, the outside surface of the sleeve at the split portion beingoutwardly coned with the small diameter of the cone adjacent the rigidportion and the large diameter remote therefrom, a rigid collar having aportion of its inside surface of slightly larger diameter than the rigidportion of the sleeve, but of less diameter than the large end of thesleeve at the outer terminus of the splits, a pipe fitted in the sleevefrom the split end and engaging the said shoulder, the said collarhaving one end jammed on the coned portion of the sleeve to clamp thesleeve to the pipe, a supporting structure with the rigid portion of thesleeve connected thereto, the collar being entirely out of contact withsaid supporting structure.

6. In a coupling, the combination of a pipe fitting threaded at one end,a sleeve having a rigid portion with threads, the rigid portion havingan internal shoulder, a plurality of longitudinal splits extending fromthe rigid portion and terminating at the end of the sleeve remote fromthe rigid portion, the outside surface of the sleeve at the splitportion Ibeing outwardly coned with the small diameter of the coneadjacent the rigid portion and the large diameter remote therefrom, apipe fitted in the sleeve from the split end, the inner end of the pipeengaging the said shoulder, a rigid collar having its inside surface ofslightly larger diameter than the rigid portion of the sleeve but ofless diameter than the large end of the sleeve at the outer terminus ofthe splits, the said collar having one end jammed on the coned portionof the sleeve to clamp` the sleeve to the pipe whereby the assembly ofthe sleeve, the pipe and the collar may as a unit be attached to thethreads of the fitting and when so attached, the collar being entirelyout of contact with the fitting.

'7. 'In a coupling, the combination of a supporting structure having anopening, a sleeve having a rigid end portion with an internal shoulderand having longitudinal splits extending from the rigid portion to theremote end of the sleeve, exterior threads on the rigid portion and partof the split portion of the sleeve adjacent such rigid portion, thesplit part of the sleeve having its outer surface coned with the smalldiameter of the cone adjacent the ends of the threads and the largediameter of the-cone at the remote or terminus end of the splits, arigid collar having an inside diameter greater than the rigid portion ofthe sleeve and the portion having the threads thereon but of lessdiameter thanfthe large end of the sleeve remote from the rigid end,V apipe fitted in the sleeve from the split end, the end of the pipeengaging the said shoulder,

'acumen the collar being jammed on the coned part of the sleeve toattach the sleeve to the ipipe whereby the assembly of the sleeve andthe pipe may be inserted through the said opening and a nut threaded onthe threads of the sleeveV to clamp the structure having the openingbetween the collar and the nut. f

LLOYD GEORGE TERRY.

